The effect of pressure on sulphur speciation in mid- to deep-crustal arc magmas and implications for the formation of porphyry copper deposits

  title={The effect of pressure on sulphur speciation in mid- to deep-crustal arc magmas and implications for the formation of porphyry copper deposits},
  author={Vladimir Matjuschkin and Jon Blundy and Richard A. Brooker},
  journal={Contributions to Mineralogy and Petrology},
Piston cylinder experiments are used to investigate the effect of oxygen fugacity (ƒO2) on sulphur speciation and phase relations in arc magmas at 0.5–1.5 GPa and 840–950 °C. The experimental starting composition is a synthetic trachyandesite containing 6.0 wt% H2O, 2880 ppm S, 1500 ppm Cl and 3800 ppm C. Redox conditions ranging from 1.7 log units below the Ni–NiO buffer (NNO − 1.7) to NNO + 4.7 were imposed by solid-state buffers: Co–CoO, Ni–NiO, Re–ReO2 and haematite–magnetite. All… Expand

Figures and Tables from this paper

Major Element and Halogen (F, Cl) Mineral–Melt–Fluid Partitioning in Hydrous Rhyodacitic Melts at Shallow Crustal Conditions
Twenty-four internally heated pressure vessel experiments were conducted at 810–860 C, 1 5– 4 05 kbar, and oxygen fugacities (fO2)1⁄4NNO –0 5 to NNOþ2 log units (where NNO is the nickel–nickel oxideExpand
Magmatic sulfide saturation and dissolution in the basaltic andesitic magma from the Yaeyama Central Graben, southern Okinawa Trough
Abstract Magmatic sulfide saturation and dissolution are increasingly thought to play important roles in controlling the behavior of chalcophile metals in arc-related magma. However, the mechanismsExpand
The stability and composition of sulfate melts in arc magmas
The stability field and composition of immiscible sulfate melts in equilibrium with silicate magmas has been determined using experiments over a range of crustal pressures, allowing an assessment ofExpand
The sulfur concentration at anhydrite saturation in silicate melts: Implications for sulfur cycle and oxidation state in subduction zones
  • Zheng Xu, Yuan Li
  • Geology
  • 2021
Abstract Magmatic sulfur plays an important role in affecting mantle oxidation state, volcanic eruption, formation of ore deposits, and global climate change. To better understand the sulfur cycle inExpand
Early sulfide saturation in arc volcanic rocks of southeast China: Implications for the formation of co-magmatic porphyry–epithermal Cu–Au deposits
Abstract It is widely considered that arc magmas are highly oxidized, and can thus dissolve a large amount of sulfur, thereby preventing significant sulfide saturation prior to fluid saturation.Expand
Coupling of Redox Conditions of Mantle Melting and Copper and Sulfur Contents in Primary Magmas of the Tolbachinsky Dol (Kamchatka) and Juan de Fuca Ridge (Pacific Ocean)
The compositions of parental melts of Tolbachinsky Dol (Kamchatka) basalts were estimated from the compositions of olivine-hosted (Fo90.5-83.1) primitive melt inclusions in the rocks of the NorthernExpand
The importance of H2O in arc magmas for the formation of porphyry Cu deposits
Abstract Porphyry copper deposits (PCDs) hosted in subvolcanic intrusions at convergent margins are the primary world’s copper resources. However, the set of magmatic processes that lead to theExpand
Amphibole and apatite insights into the evolution and mass balance of Cl and S in magmas associated with porphyry copper deposits
Chlorine and sulfur are of paramount importance for supporting the transport and deposition of ore metals at magmatic–hydrothermal systems such as the Coroccohuayco Fe–Cu–Au porphyry–skarn deposit,Expand
Low-Ca boninite formation by second-stage melting of spinel harzburgite residues at mature subduction zones: new evidence from veined mantle xenoliths from the West Bismarck Arc
We report the abundances of major and lithophile trace elements and volatiles (H2O, Cl and S) in orthopyroxenite veins cutting mantle-derived, spinel harzburgite xenoliths from the active RitterExpand
T-P-fO2 conditions of sulfide saturation in magmatic enclaves and their host lavas
Physicochemical conditions under which early sulfide saturation occurs and the role of this process in the mineralising potential of magmas in different geodynamic settings have been the subject ofExpand


Temperature dependence of sulfide and sulfate solubility in olivine-saturated basaltic magmas
Abstract The sulfur concentration at pyrrhotite- and anhydrite-saturation in primitive hydrous basaltic melt of the 2001–2002 eruption of Mt. Etna was determined at 200 MPa, T = 1050–1250 °C and atExpand
Distribution of Sulfur Between Melt and Fluid in S-O-H-C-Cl-Bearing Magmatic Systems at Shallow Crustal Pressures and Temperatures
Volatile constituents dissolved in magmatic fluids control fundamental geologic processes including magma ascent, degassing, and eruption; metasomatism; and hydrothermal mineralization in the shallowExpand
Anhydrite solubility in differentiated arc magmas
Abstract The solubility of anhydrite in differentiated arc magmas was experimentally studied at 200 MPa and 800–1000 °C over a range of oxygen fugacities, from 0.5 log units above the Ni–NiO bufferExpand
An evaluation of the effect of degassing on the oxidation state of hydrous andesite and dacite magmas: a comparison of pre- and post-eruptive Fe2+ concentrations
The bulk (post-eruptive) wt% FeO concentration in each of 11 phenocryst-poor (<5%) andesite and dacite (60–69 wt% SiO2) lavas from different monogenetic vents in the Mexican arc has been measured byExpand
Abstract The sulfur contents at sulfide saturation (SCSS) of a basaltic and a picritic melt have been measured experimentally as a function of pressure and temperature from 5 to 90 kb andExpand
Speciation and solubility of reduced C–O–H–N volatiles in mafic melt: Implications for volcanism, atmospheric evolution, and deep volatile cycles in the terrestrial planets
Abstract Using vibrational spectroscopy and SIMS, we determined the solubility and speciation of C–O–H–N dissolved volatiles in mafic glasses quenched from high pressure under reduced conditions,Expand
Carbon dioxide in magmas and implications for hydrothermal systems
Abstract. This review focuses on the solubility, origin, abundance, and degassing of carbon dioxide (CO2) in magma–hydrothermal systems, with applications for those workers interested inExpand
Sulfur concentration at sulfide saturation (SCSS) in magmatic silicate melts
Abstract The sulfur concentration in silicate melts at sulfide saturation (SCSS) was experimentally investigated in a temperature range from 1150 to 1450 °C and a pressure range from 500 MPa to 1 GPaExpand
An Experimental Study of the Sulfur Content in Basaltic Melts Saturated with Immiscible Sulfide or Sulfate Liquids at 1300°C and 1·0 GPa
The sulfur content in basaltic melts coexisting with either sulfide or sulfate melts was determined experimentally. The experimental conditions were in the range of 1300–1355 � C and 1� 0– 1� 6GPa,Expand